Block access to an IP that is on the LAN network

From:	"Matt Ketelsen" <ketelsen at nobel dash net dot com>
To:	<m0n0wall at lists dot m0n0 dot ch>
Subject:	Block access to an IP that is on the LAN network
Date:	Thu, 26 Oct 2006 15:34:27 -0500

Is there a rule that I can make to block requests to a single ip?  As in I
have a computer on the LAN and I don't want any other computers within the
LAN to see it.  I would rather not deal with installing firewall software on
the machine that I want hidden.